pmopenlog(3) — Linux manual page


PMOPENLOG(3)            Library Functions Manual            PMOPENLOG(3)

NAME         top

       pmOpenLog - create a log file for diagnostics and debug output

C SYNOPSIS         top

       #include <pcp/pmapi.h>

       FILE *pmOpenLog(const char *progname, const char *logname,
               FILE *oldstream, int *status);

       cc ... -lpcp

DESCRIPTION         top

       pmOpenLog reassigns the standard I/O stream oldstream (normally
       stderr) to be associated with the file logname.  If logname is
       not "-" and already exists, it will be removed and recreated if
       possible (to ensure correct ownership and permissions from the
       caller to pmOpenLog).

       As a special case, if logname is "-" then no removal or reopening
       is performed and the function simply sets status to 1 and returns
       oldstream.  This is useful when the caller wants diagnostics on
       oldstream stream (normally stderr) rather than a file, e.g.
       pmlogger -l- or pmcd -f -l-.  Logging to stderr is also useful
       for PMDAs in a containerized environment where it is beneficial
       for all PMDA logs to be written to pmcd's stderr stream (and thus
       to a single destination), whether that is a file such as pmcd.log
       or the original stream inherited from the shell.

       On return, the function value is the standard I/O stream,
       possibly replacing oldstream.  In the event of an error, the
       return value will be oldstream unchanged and status will be 0.

       For success, status is 1, and a standard preamble is written to
            Log for progname on hostname started date and time
       and an atexit(3) handler is installed to write the postscript
       message to logname
            Log finished date and time
       when the processes exits.

       progname is only used to annotate messages.

SEE ALSO         top

       atexit(3) and freopen(3).

COLOPHON         top

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Performance Co-Pilot               PCP                      PMOPENLOG(3)

Pages that refer to this page: pmnotifyerr(3)